Turning over engines in storage

I don't know about the WD-40. I was a gun enthusiast and armourer and wd-40 is not good. it contains a varnish. it is ok to keep things moving but for storage, I can see the wd-40 sinking into the metal and hurting the porous metal in the cylinders. I would use a heavy grade oil sae30 or sae40 and a good old fashioned pump oil can and give a good squirt. Again this is just based on experience with firearms.